In the practice of abdominal surgery, which requires the examination and manipulation of intraperitoneal and extraperitoneal organs and tissues, surgeons most often employ a long established technique of opening the abdominal wall with an incision large enough to accommodate instruments required, as well as the surgeon's hands, and to allow procedures such as anastomosis or removal of diseased organs or portions thereof. The advantages of this technique include a large degree of freedom of motion for successfully completing the procedure, sufficient space for mechanical leverage which may be necessary, and above all, tactile feedback response to the surgeon when using his hands to feel the texture, temperature, and physical response of the tissues. The disadvantages of this traditional technique, however, include long healing and recuperative time with considerable post-operative pain, and adhesion formation which can cause pain and bowel obstruction. Additionally, the traditional technique may increase the complexity of later surgery, as well as increase the possibility of post-operative morbidity and unsightly scars remaining after the procedure is completed.
In order to overcome the disadvantages of the traditional abdominal surgery method using a large incision, laparoscopic techniques have been developed which use several smaller puncture openings in the abdominal wall. These openings are used to inflate the abdominal cavity with a gas to elevate the abdominal wall away from the organs, and to allow room for the manipulation of the organs. The openings also provide means to introduce light generating and optical viewing instruments to observe the abdominal cavity, and to manipulate the organs in order to accomplish the desired results. This laparoscopic technique is becoming widely accepted because of its many advantages. These advantages include reduced adhesions, shorter recovery time, and less post-operative pain. There are also some disadvantages. For example, there are limitations on freedom to manipulate organs, and the surgeon's viewing ability, although magnified with the aid of a laparoscope, lacks depth perception. Most importantly, there is a lack of tactile feedback of the tissue through the surgeon's hands. Also, when a tissue specimen must be removed, a larger opening must be made in the abdominal wall near the end of the procedure, causing loss of gas pressure, collapse of the abdominal wall, and loss of interior working and viewing space.
The laparoscopic technique uses smaller puncture openings in the abdominal wall as described. These openings are usually made with a puncture device called a trocar. The trocar point and attached shaft are usually contained in a hollow circular tube which remains in the abdominal wall after puncture and through which other instrument shafts are passed to be used in the operating procedure. A sealing feature must be included in the trocar cannula body in order to maintain the gas pressure as described above. Various sizes and shapes of instruments are used in these procedures and sealing between the instruments and the trocar body must be achieved. Also, internal sealing is required within the instrument body passing through the cannula to avoid gas leakage. The importance of these sealing requirements is indicated by their inclusion in endoscopic instrument patents. For example, U.S. Pat. Nos. 5,104,383 and 5,197,955, describe sealing mechanisms between trocars and instruments passed through them. Also, the endoscopic instruments themselves contain internal sealing means to reduce the loss of gas pressure in the abdominal cavity. U.S. Pat. Nos. 5,100,420 and 5,171,249, describe internal sealing means in endoscopic instruments.
Combining the advantages of the traditional and the laparoscopic techniques for abdominal surgery is the laparoscopic assisted procedure. In this procedure, the normal laparoscopic small puncture openings are made with the exception that one opening is made late in the procedure and large enough to allow a surgeon's hand to pass through the abdominal wall in order to remove tissue or deliver a mobile organ for surgery. When this larger opening is made, gas pressure is lost and the procedure must be completed by using a plug usually made of gauze to seal the opening to allow reinflation. This sequence of: removing the plug, losing gas pressure, performing a surgical step, replugging the opening, and reinflating the abdominal cavity can be repeated several times before the surgical procedure is completed.
Accordingly, it is an object of the present invention to allow the advantages of the laparoscopic method of maintaining gas pressure in the abdominal cavity, and of requiring relatively small incisions for quicker recovery than the traditional method, yet allows the surgeon the important feature of tactile feedback to determine directly the information needed to successfully conclude the procedure as well as allow removal of the specimen.
In addition, it is an object to provide a unique gas pressure sealing means that can be used to seal between an abdominal wall opening and a surgeon's hand in addition to a sealing means that can be used in a trocar device to seal between the trocar housing and any instrument which can pass through the trocar tube.
Another object of the present invention is to seal the abdominal cavity or trocar device when nothing is placed through the sealing device in order to maintain gas pressure in the abdominal cavity.
Furthermore, another object of the present invention is to provide a sealing means between the trocar cannula and the different instruments which are passed through the trocar cannula for use during the operating procedure as well as maintaining gas pressure when no instruments are inserted in the trocar cannula.